title: Health risks of space exploration: targeted and nontargeted oxidative injury by high-charge and high-energy particles.
abstract: CONCLUSIONS
  During deep space travel, astronauts are often exposed to high atomic number (Z) and high-energy (E) (high charge and high energy [HZE]) particles. On interaction with cells, these particles cause severe oxidative injury and result in unique biological responses. When cell populations are exposed to low fluences of HZE particles, a significant fraction of the cells are not traversed by a primary radiation track, and yet, oxidative stress induced in the targeted cells may spread to nearby bystander cells. The long-term effects are more complex because the oxidative effects persist in progeny of the targeted and affected bystander cells, which promote genomic instability and may increase the risk of age-related cancer and degenerative diseases.
  
  
  BACKGROUND
  Greater understanding of the spatial and temporal features of reactive oxygen species bursts along the tracks of HZE particles, and the availability of facilities that can simulate exposure to space radiations have supported the characterization of oxidative stress from targeted and nontargeted effects.
  
  
  RESULTS
  The significance of secondary radiations generated from the interaction of the primary HZE particles with biological material and the mitigating effects of antioxidants on various cellular injuries are central to understanding nontargeted effects and alleviating tissue injury.
  
  
  CONCLUSIONS
  Elucidation of the mechanisms underlying the cellular responses to HZE particles, particularly under reduced gravity and situations of exposure to additional radiations, such as protons, should be useful in reducing the uncertainty associated with current models for predicting long-term health risks of space radiation. These studies are also relevant to hadron therapy of cancer.
authors.affiliation: 1 Department of Radiology, Cancer Center, Rutgers University-New Jersey Medical School , Newark, New Jersey.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Géraldine
authors.initials: G
authors.lastname: Gonon
authors.forename: Manuela
authors.initials: M
authors.lastname: Buonanno
authors.forename: Narongchai
authors.initials: N
authors.lastname: Autsavapromporn
authors.forename: Sonia M
authors.initials: SM
authors.lastname: de Toledo
authors.forename: Debkumar
authors.initials: D
authors.lastname: Pain
authors.forename: Edouard I
authors.initials: EI
authors.lastname: Azzam
mesh_terms: D000818:Animals; D003359:Cosmic Radiation / Q000009:adverse effects*; D018470:Gravity, Altered; D006801:Humans; D010084:Oxidation-Reduction / Q000528:radiation effects; D018384:Oxidative Stress / Q000528:radiation effects; D011839:Radiation, Ionizing; D017382:Reactive Oxygen Species / Q000378:metabolism; D013026:Space Flight
chemical_list: D017382:Reactive Oxygen Species